> My output looks a little strange; for some subjects I have a significant ring effect around the head but
> I removed motion from my ROI time series and included motion as regressors of no interest in the
> final 3dDeconvolve.

The ring effect could be caused by severe head motion or some other scanner-related issues. You may have to look into the original data closely and figure out the source of the problem. The head motion correction (plus including the estimated effects as regressors in the model) may not be good enough to handle the impact if the situation is bad.

> Also when I do the group analysis and look at the grps vs 0, I have to turn the threshold so far up to
> get legible results and again there are rings around the head although the 2 sample ttests look reasonable.

Do you mean that the clusters are so huge that you have to raise the threshold bar to see anatomically meaningful regions?

Gang



Edited 1 time(s). Last edit at 10/14/2014 03:31PM by Gang.